1. Field of the Invention
This invention relates generally to sailboats and more particularly to the shape of hulls for larger sailing catamarans.
2. Discussion of the Prior Art
One of the most perplexing problems encountered by sailboats is to find the ultimate shape to provide high speed while increasing the stability of the boat.
Several prior art boats have attempted to resolve the problems. First is Canadian Patent No. 307,326 to Mallison (U.S. Pat. No. 1,705,413) which describes a boat with a tunnel hull. Although "catamaran" is mentioned in the patent, it is closer to a monohull boat with twin keels, inasmuch as the complete tunnel is under water and the boat can therefore not be called a catamaran. The two appendages (twin bilges) are claimed to increase stability and there is a reference to "resisting drift" and "rapidity of travel". The boat will travel no faster than a monohull sailing boat in light wind and will be slower than a normal sailing boat with a single keel in higher winds due to the increased wetted area. This boat will not perform like a catamaran, since the bilges are too narrowly spaced to prevent heeling in any appreciable way.
U.S. Pat. No. 3,877,406, describes a boat which only carries the mast and the sail used to pull a person through the water. The "keel" of this boat is the body of the person which is submerged between the floats. The vertical insides of the floats are to prevent a bow wave, which would presumably be very small in any case, judging by the low weight of the assembly and the very low speed attainable while dragging a person through the water.
Canadian Patent Application Serial No. 2,043,801 describes a trimaran of unconventional configuration, tricycle style where the central pontoon (hull) is performing the steering function (no rudders in back) and is far ahead of the lateral pontoons. The sharply hooked lateral pontoons are described to function whereby leeway preventing function is relegated to the windward pontoon and the leeward pontoon presents a shallow angle to sideways movement. This "riding up" is supposed to prevent heeling. First, the pontoons as depicted do not have enough buoyancy to support the structure above water, and secondly, if leeway is efficiently prevented by the windward pontoon then there will be no generated lift from any sideways movement. If leeway is not prevented, then the whole concept will not work.